Alumina containing catalyst



ALUMINA CONTAINING CATALYST.

Philip A. Lefrancois, Cranford, N. J., assignor to The M. W. KelloggCompany, Jersey City, N. J., a corporation of Delaware No Drawing.Application April 21, 1952 Serial No. 283,517.

10 Claims. (Cl. 252-455) This invention relates to a novel'catalyticmaterial and also to a method of preparing the same, and moreparticularly pertains to a novel catalytic material containing aluminawhich is especially adapted-for catalytic reactions, e. g., hydrocarbonconversion.

An object of this invention is to provide a novel alumina containingcatalytic material.

Another object of this invention is to provide a novel method forpreparing an alumina containing catalyst.

Still another object of this invention is to provide a novel catalyticmaterial containing'alumina which is especially adapted for thecatalytic conversion of hydrocarbons.

A further object of this invention is to provide a catalytic materialcontaining alumina which is particularly adapted for the reforming ofhydrocarbon oils, e. g., petroleum naphthas.

Other objects and advantages of this invention will become apparent fromthe following description and explanation thereof.

In accordance with the present invention, a novel catalytic materialcontaining alumina is provided which is prepared by the methodcomprising the reaction of United States Patent 2,840,529 Patented June24, 1958 2 combination with the alumina and the catalyticagent describedabove. For this purpose the silica is employed in amounts of about 0.5to about 15% by weight of'the catalyst. In addition to the effect ofimproving the heat stability of the catalyst by means of silica, itisalso de-. sirable to add silica to the platinum and/ or palladium catealyst in small amounts for the purpose of inhibiting undesirablecracking effects. Such undesirable effects can be inhibited by the useof about 0.05 to about 15% by weight of silica, preferably about .5 toabout ,l0% by weight based on the total catalyst.

Under certain conditions, it is desirable/to incorporate into the finalcatalyst an additional carrier material. In this respect, the aluminaprepared in accordance with the present invention can be used incombination with kiesel- I guhr, pumice, fullers earth, bentonite clays,.Super-v aluminum, water and an activating agent selected from the groupconsisting of an element which is situated below. aluminum in theElectromotive Series and/ or a compound thereof at an elevatedtemperature sufficient to.

initiate the reaction, and then combining therewith the catalytic agentselected from the class consisting of an element of groups IB, III, IV,V, VI and VIII in the periodic table and the sulfides and oxidesthereof.

The catalytic agent which is employed in combination with the aluminacan be one or more of the elements of groups IB, III, IV, V, VI and.VIII in the periodic table, or such an element can be used in the formof :a sulfide and/ or oxide. Specific examples of the catalytic agentare silica; boria; copper; silver; iron; platinum; palladium; tungsten;and/or the'oxides and sulfides of chromium, molybdenum, vanadium, iron,cobalt, nickel, tungsten, etc. The amount of catalytic agent present inthe catalyst will vary depending upon the particular use for which thecatalyst is intended. Generally, however, the catalytic agent comprisesabout 0.1 to. about 40% .by weight of the total catalyst. When thecatalyticmaterial is intended primarily for a catalytic crackingoperation, the catalytic agent is preferably about 60 to 95% by' weightof the total catalyst. With respect to a reforming operation, it ispreferred that the catalytic agent constitutes about 0.1 to about 30% byweight of the total catalyst.

Particularly effective types of cracking catalysts include,

for example, silica-alumina, boria-alumina, silica-magnesia, etc. Inthis regard, preferred catalysts for hydroforming operations include,'for example, the oxides filtro ,f etc. Whenever an additional carriermaterial is employed in the catalyst, it is desirable to use about 2 toabout 50% by weight, preferably about 5 to about 25 by weight of thesame, based on the total catalyst. This auxiliary carrier material mayserve to lessen the instability of the alumina at elevated temperaturesand also to enhance its catalytic properties with respect to certain specific uses, such as for example, ,in the case of catalytic cracking,hydroforming, hydrogenation, dehydrogena tion, etc. a

The aluminais prepared by reacting aluminum metal, water and anactivating agent-at an elevated temperature which is suflicient toinitiate the reaction. The aluminum: in the metallic state is useful inany physical form fo'r the intended reaction, for example, thelaluminummetal'c'an be furnished in the form of metal strips, sheets, pellets,

lumps, turnin-gs, in powdered or finely divided form, etc. Aluminum inthe metallic state, if exposed to the atmos-' phere for an appreciableperiod of time will become oxidized and form an aluminum oxide coatingon the surface thereof. For the purposes of this invention, it ispreferred that the aluminum metal be substantially free of the oxidecoating in order that the reaction may proceed at a-reaof such a metalwhich will serve to activate the reaction,

The activating agent appears to create an electromotive potential withthe aluminum metal, and in this manner, the reaction between thealuminum and the water is facilitated. As long asthe activating agentcontains a metal which is below. aluminum in the electromotive series,j'the{ electromotive potential is created with the aluminum. Howeveninthis respect, it is preferred to employ an activating' agent which willcreate with the aluminum an electromotive potential of at least about0.2 volt in order A to avoid or substantially overcome any tendencyfor:po-.

larizing eflfects to occur. The polarizing effects which might occur aredue to, the presence of hydrogen on--the surface of the reactingmaterials. Generally, the activate ing agent is employed in an amount ofabout 0.000510 its b l e fi e ei l e t e lts. cont ining the alk linewit me a s hi h hav b en termed I i h e k a id A q hr lui eb esl s an ak lin reagent includes, for example, ammonia and substituted 3 are lowerthan aluminum in the electromotive series and/or the compounds thereof.In the form of a compound, the activating agentgcan be either an organicor ii ss mr iw P! t e n h m of a n- P i the a ti t n aeqet au be d to:exampl s i one. h de (fluor e. queu m d and iodide), nitrate, sulfate,carbonate, nitrite, sulfite, phospliate, oXy haIide, hydroxides,formates, acetates, propionatesQalkyl or aryl'or mixed metallocompounds, basic carbonates, chromates, cyanides, oxalates,silicofluorides, etc. "Specific examples of compounds which can be usedas aetivating agents'are mercuric oxide, mercuric acetate, mercu'iouschloride, silver nitrate, rhodium chlon'rleQetc.

In order to initiate the reaction between aluminum andwaterin thepresenceof an activating agent, an elevated temperature isemployed.Generally, a temperature of atleasft about 150 'FQfor more usually,in'the range of abput. 17 5310 about 300 F. is satisfactory to comrnencethe reaction. Normally, the reaction will proceed satisfactorily atatmospheric pressure. However, in some instances, it may be desirable toconduct the reaction at super-atmospheric pressure in order to enablehigher temperatures to be used. When the reaction is conducted at highertemperatures, it islto he expected that the rate ofreaction is fasterand, therefore, less time 'may be r required in the preparation ofthe-alumina. For this purpose, apressure in the order of about 25 toabout 500 p. s. i. -g., will be satisfactory for the purpose ofeffecting a faster rate of reaction between the aluminum and water. i pv Thealumina which has been prepared by reacting aluminu'm and water inthe presence of the activating agent 4 with an alkaline reagent with orwithout a suitable aging period, the amount of eta-alumina is increasedover the amount which is usually priesent in the alumina derived withoutthe pH adjustment.

Various techniques can be used for preparing the catalytic material. Inone instance, the alumina as a slurry or in the dried and/or calcinedform is combined with a catalytic agent in the form of a suitablecompound which upon calcination will produce the desired catalyticstate. In thecase of preparing a catalyst containing molybdenum oxide,the alumina can be mixed with ammonium molybdate as an aqueous solution,molybdenum trioxide in the solid form, or the alkali metal salt ofmolybdic acid, etc., and then dried with subsequent calcination. Onespecific procedure. involves mixing the aqueous solution of catalyticagent in suitable form with either a slurry of alumina, dried alumina orcalcined alumina, followed by a drying step and then calcination.Another method of preparing molybdena catalyst is to mix the aluminaslurry, the dried alumina or the calcined alumina with molybdenumtrioxide in the solid form followed by a drying step, if necessary, andthen calcination at an elevated temperature in the order of about 700 toabout 1500' F. The preparation of platinum catalysts involves combininga slurry of alumina, the dried alumina or calcined alumina with acompound of platinum, such as for example, platinum sulfide, platinumammine complex, ammonium and alkali metal salts of chloroplatinic acid,etc. After combining the demny be used without further treatment forpreparing the finishedwcatalyst. Normally, the, alumina slurry thusproduced has apH in the range'of about 7.5 to about 9.5. It was.observed thatthe alumina does not under gnachange, to a gel form evenwith an alkaline treatment lqraise, the pH above the level at which itis nor-. mally found-asaresult of theinitial stage of preparation. ,Jtwas also found, however, that treatment. of the b ended to includetreating the alumina with an 4 9 999 retrea 9. 24?! a se e p t at leastabout 8. with i h a in f9. a suitable p r od o ime?! i". #1 4 a ut tipThe lkalin ea e am onium compounds. Specific examples of alkalinereagents are ammonium hydroxide, tetrarnethyl ammonium hydroxice, sodiumhydroxide, potassium hydroxide, isoamylam:.ne, butyl amines,diethylamine, piperidinegetc.

General y, in treating the alumina with an alkaline refor thepurpose oftreating the alumina, will'dependuponthe 'pH adjustment required; 1 lnone aspect,

sired components, the mixture is dried, if necessary, and then calcinedat an elevated temperature. For another preparation of catalyst, it isdesirable to use the catalytic agent in a form which will readilydisperse or distribute throughout the carrier material in order toobtain catalysts of high activity. The precursor state of the catalyticagent is well known to those skilled in the art and, therefore, itshould be understood that such forms of catalytic agent can be used inthe present invention for the preparation of the finished catalyst.

As previously indicated, it is contemplated employing small amounts ofsilica along with the alumina in the catalytic material. The silica canbe added in the form of silicon tetrachloride, an alkyl ester oforthosilicic acid,

" e. g., ethyl ortho-silicate, methyl ortho-silicate, propylortho-silicate, cracking catalyst hydrogel (silica-alumina,silica-magnesia), fluorosilieic acid. magnesium fluorosilicate, etc. Thesilica forming substance can be added directly to the slurry of alumina,the dried alumina or the calcinedalumina, prior to mixing with theprecursor material of the catalytic agent. Alternatively, thesilicaforming substance can be addedto the mixture of catalytiej agentand alumina'containing substance, prior to the drying and] orcalcination treatments. In some instances,

it may be desirable to prepare the calcined. catalyst containing aluminaand, the. catalytic agent and then mixing the same witha solid or gel ofsilica followed by a drying operation and then calcination at anelevated temperature. In addition, the siliceous material may be addedat the start of the aluminum, water, activating agent reaction.

' greater than about 400 F., or more usually, at a temagent; it ispreferredto employ, ammonium hydroxide because this reagent does notleave any residue in the catalyst which would tend to cause anyundesirable effl .fects. The quantity of alkaline reagent which ispreperature in the order of about 200 to about 250 F. At temperatures inthe range given, drying isconducted for a period of up to about 60hours,or more usually,

for a periodof about 15 to about 50 hours. The drying operation, isfollowed by at calcination treatment which is etfected'fat an elevated,temperature, of at least about 700 .F. and up to about 1450" F., moreusually, the,

ealcination; treatment, is accomplished at a temperature in the, rangeof about 1 000. to about1250 F. Calcinaabout 3 to about 6 hours. Atcalcination temperature, if the catalytic agent is employed in aprecursor state for the purpose of being distributed uniformlythroughout the catalyst mass and is not catalytically active, theprecursor material is converted to the active catalytic form. In thismanner, the catalytic agent is distributed uniformly on the carriermaterial and is then converted to the active state at calcination insubstantially the same positions on the carrier as it was present in theprecursor state.

Among the numerous reactions which lend themselves to catalysis in thepresence of contact materials of the type disclosed herein aredehydrogenation, hydrogenation, hydrogenolysis, isomerization,oxidation, aromatization, cyclization, hydrodesulfurization, hydrocarbonsynthesis, dealkylation, dehydroxylation, alkylation, polymerization andhydrogen exchange systems. In general, these reactions may be carriedout under the conventional reaction conditionsof temperature, pressure,etc., with the catalysts described herein.- However, in many instances,the activity of the new contact materials permits the employment of lesssevere conditions, especially lower temperatures and contact times,without any sacrifice in selectivity. A wide variety of organiccompounds may be dehydrogenated including naphthenes, paraffins, alkylradicals in aralkyl compounds, butenes, sterols, glycerides and manyother organic compounds. By changing the reaction conditions in knownmanner, these catalysts are also effective for hydrogenation of organiccompounds in general, and especially fatty glycerides and olefins. Theymay also be employed in the hydrogenolysis of nitrobenzene to anilineand similar chemical changes. The dehydroxylation or demethylation, orboth, of cresylic acid-type compounds may also be carried out in thepresence of such contact materials. Among the substances which can beisomerized with these catalysts, paraffins and naphthenes are the mostsignificant feeds from a commercial standpoint; but polyalkyl aromaticsmay be similarly treated, as exemplified in the catalytic transformationof o-xylene to p-xylene. The contact materials of the present inventionare especially suitable for cracking in the presence of hydrogen as inthe hydroforming process in which the feed is customarily a low octanenaphtha; In hydroforming by the present catalytic process a substantialdegree of sulfur removal occurs and the reaction may readily be shiftedto favor hydrodesulfurization rather than reforming by changing thereaction conditions in a manner familiar to those skilled in the art.The synthesis of hydrocarbons from carbon monoxide and hydrogen in thepresence of the new contact materials is also contemplated. In the fieldof oxidative reactions, numerous changes can be effected with thepresent catalysts including, inter alia, the transformation of sulfurdioxide to sulfur trioxide, the formation of nitric acid and alsohydrazine from ammonia, the conversion of urea into hydrazine and theoxidation of hydrocarbons in general. The contact materials employed inthe present invention are also suitable for hydrogen exchange systems asexemplified by the hydrogenation of coal with decalin and tetralin. Byreason of their aromatizing and cyclizing characteristics they areoutstanding in preparing benzene, toluene and the like in substantialyields from parafiins and naphthenes and also for the production of morehighly cyclized compounds such as naphthalene, anthraceneandalkyl-substituted derivatives thereof under suitable conditions. In

. .addition, polymerization and alkylation reactions are responsive tothese catalysts; for example, the polymerization of olefins and thealkylation of aromatic compounds.

The catalysts of the present invention are particularly adapted forreforming naphtha stocks. In reforming naphtha or gasoline stocks withthe catalyst disclosed ,herein, the conditions may be varied ratherwidely; thus :temperatures of about 600 to about 1050' F. are suitableand the preferred range is from about 900 to about 950 F. Within thesetemperature limits, weight space velocities of about 0.05 to about 10.0pounds of naphtha per hour per pound of catalyst in the reaction zonemay be employed advantageously; however, space velocities of about 0.25to about 5.0 provide the best results. Hydrogen should be introducedinto the reforming reactor at rates running from about 0.5 to about 20.0mols of hydrogen per mol of hydrocarbon reactants. This hydrogen may bein admixture with light gaseous hydrocarbons. In fact, it is usuallyintroduced by recycling the normally gaseous products, chiefly hydrogenalong with about 10% more or less of hydrocarbons containing 1-3 carbonatoms of the reforming reaction. The hydrogen serves an importantfunction in maintaining the activity of the contact material byminimizing coke deposition thereon. While the total reaction pressuremay be minimized at any value between about 50 and 1000 pounds persquare inch gauge (p. s. i. g.), the best results are obtained byholding the reaction pressure within the range of between about andabout 750 p. s. i. g. The conditions can be varied to include operationswherein there is a net consumption of hydrogen as well as a netproduction of hydrogen as in hydro-forming.

The catalysts of this invention can be employed in processes involving astatic or a fluid bed of catalyst, and the systems can involve a fixedbed or a circulating bed. In any case, the catalyst can be in lump,granular or finely divided form. Granular catalyst may have a particlesize of about 0.1 to 10 mm., average diameter; whereas the powdered orfinely divided catalyst may have a particle size of about 5 to about 250microns, or more usually, about 10 to about 100 microns. In a moving bedsystem, generally a catalyst to oil ratio, on a weight basis, of about0.05 to about 20, or more usually, about 0.1 to about 10, preferablyabout 0.5 to 2.5 is employed.

In order to more fully understand the presentinvention reference will behad to examples of catalyst preparations, however, it should beunderstood that no undue limitations or restrictions should be imposedby reason thereof.

CATALYST I The alumina slurry was prepared by reacting 12,819 grams ofaluminum pellets, 18 liters of distilled water and 65 grams of mercuricoxide. In order to initiate the reaction, the reaction mixture washeated with steam for 6 minutes until boiling occurred. After reactingthe mixture for a period of 1 /2 hours, it was poured through acheesecloth in order to remove any unreacted and/or solid materialscontained therein. The filtered alumina slurry weighed 15,635 grams at155 F. It possessed a density of 1.062 grams per cc. at F. and a pH of7.83 at 29.5 C., and ignition loss showed 8.64% solids, thus indicatingthat 1350 grams of A1 0 were produced.

6850 grams of alumina slurry (600 grams of A1 0 were poured into a trayand dried in a Grieve-Hendry oven at 240 F. for a period of 19% hours.Since the alumina was not completely dry, it was placed in a Despatchoven and dried at 240 F. for an additional 2% hours. The dried aluminawas ground to a powdered form and then calcined for 3 hours at 1200 F.The calcined alumina Weighed 594 grams before being impregnated with asolution of 72.0 grams of ammonium molybdate ((NH4)6M070244H30)dissolved in 500 cc. of distilled water. An additional 210 cc. of waterwere added in order to completely wet the alumina.

The impregnated alumina was dried in the Grieve- Hendry oven at 240 F.for 18 hours, and thereafter, cal: cined for 3 hours at 1200 F. Thefinished catalyst contained 90.83% alumina and 8.97% M00 based on thetotal catalyst.

In the example of catalyst preparation given below, the alumina/wasdried by-a s'pray drying technique,

"7 otherwise the .precedure is substantially the same as given aboveunder Catalyst 1.

CATALYST II 8553 grams of alumina slurry prepared in accordance with themethod described in Catalyst I were spray dried in a Niro unit using thefollowing conditions: an inlet temperature of 400 C., an outlettemperature of 115 C. and a feed rate of 85 cc. per minute. The Nitrolaboratory spray dryer consists of a direct fired gas heated chamber inwhich the material to be dried is fed into a centrifugal atomizerrevolving at about 50,000 R. P. M. The dried powder is pneumaticallyconveyed to a cyclone separator where the dried powder is collected. Thespray dried alumina weighed 1005 grams and by ignition loss 68.09%solids were produced thus indicating the presence of 685 grams of A1 Thespray dried alumina powder was calcined for 3 hours at 1200 F. in aHoskins furnace. The alumina thus calcined was then impregnated with asolution containing 68.3 grams of ammonium molybdate ((NH Mo O -4H O)dissolved in 500 cc. of distilled water. An additional 450 cc. of. waterwere added in .order to completely wet the alumina. The impregnatedalumina was dried in an Elconap oven at 240 F. for a period of 17%hours. Thereafter, the dried catalyst was calcined for 3 hours at 1200F. The finished catalyst contained 88.76% A1 0 and 9.00% M00 and a traceof Fe o CATALYST III In order to evaluate the stability of Catalyst IIit was calcined for a 6 hour period at 1470 F.

In the example given below, the pH of the alumina slurry was raised inorder to determine the effect, if any, on catalyst activity.

CATALYST IV The alumina slurry was prepared by reacting 12,819 grams ofaluminum pellets, 18 liters of water and 65 grams of mercuric oxide. Thereaction was initiated by introducing steam into the reaction mass whilestirring the same. After injecting steam for a 3 minute period the massseemed to be boiling, hence, the injection of steam was discontinued.The reaction was allowed to proceed for 1% hours and then the mass wasfiltered through cheesecloth in order to remove any unreacted materialsand/ or solid material. The filtered alumina slurry weighed 15,387grams, it had a density of 1.069 grams per cc. at 148 F. and a pH of8.46 at 32.5 C.

The pH of the alumina slurry was adjusted to 10.20 at 28 C. by theaddition of 50 cc. of concentrated ammonium hydroxide (28-30% ammonia).The treated alumina was permitted to age for a period of 17 hours whilebeing stirred slowly. The aged alumina slurry had a pH of 10.00 at 22.5C. The aged alumina weighed 14,548 grams.

Approximately 7274 grams of the aged alumina were spray dried in a Nirounit using the following conditions: an inlet temperature of 400 C., anoutlet temperature of 115 C. and a feed rate of 82.5 cc. per minute. Asa result of spray drying 809 grams of alumina powder were produced. Thespray dried alumina was then calcined for 3 hours at 1200 F. Thecalcined alumina weighing 550 grams was impregnated with a solutioncontaining 67.1 grams of ammonium molybdate dissolved in 750 cc. ofdistilled water. An additional 170 cc. of water were added in order'tocompletely wet the alumina. The impregnated catalyst was then dried inan Elconap oven at 240 F. for 16 hours; The dried catalyst was thencalcined for 3 hours at 1200 F. The catalyst contained 8.73% M00 and theremainder being approximatelyall alumina. V

In the following example, the/catalyst was prepared 8 in essentially thesame manner as given above under Catalyst IV, except that it was driedin an oven rather than by the spray drying technique.

CATALYST V 7274 grams of the aged sol prepared in the manner describedabove under Catalyst IV were dried in a Grieve- Hendry oven for a periodof 24 /2 hours at 240 F. The dried alumina was then ground into apowdered form and weighed 928 grams. The powdered alumina was calcinedfor 3 hours at 1200 F. The calcined alumina weighing 662 grams wasimpregnated with a solution containing 79.3 grams of ammonium molybdatedissolved in 500 cc. of water. An additional 410 cc. of water were addedin order to completely wet the alumina. Thereafter, the impregnatedalumina was dried for 21% hours at 240 F. in a Grieve-Hendry oven. Thedried catalyst was then calcined for 3 hours at 1200 F. The finishedcatalyst containing 90.72% alumina and 9.01% M00 In the example givenbelow, the catalyst was prepared by mixing alumina sol directly with theammonium molybdate solution rather than by the impregnation of thecalcined alumina with the activating agent.

CATALYST VI The alumina slurry was prepared by reacting 12,820 grams ofaluminum pellets, 18 liters of water, and 65 grams of mercuric oxide.The reaction was initiated by introducing steam for five minutes intothe reaction mass while stirring the same. The reaction was allowed toproceed for 1% hours and then the liquid mass was filtered throughcheesecloth. The filtered alumina slurry, weighing 15,595 grams, had apH of 8.90, a density of 1.066 grams per cc. at 40 C., and contained1211 grams of alumina.

Part of the alumina slurry, weighing 7729 grams and containing 605 gramsof alumina, was activated with a solution containing 73.2 grams ofammonium molybdate ((NH4)6MO7O244H2O), dissolved in 350 cc. of distilledwater. The activated alumina slurry after hour of agitation gave a pH of7.41 at 275 C.

The activated slurry was spray dried in the Niro unit at an inlettemperature of 400 C., an outlet temperature of 125 C. and a feed rateof cc. per minute. The spray dried powder, weighing 940 grams, wascalcined for 3 hours at 1200 F. The calcined powder weighed 632 grams.The catalyst contained 8.84% M00 and the remainder being substantiallyall A1 0 The example below illustrates a catalyst preparation of drymixing of the activating agent with the alumina.

CATALYST VIII The alumina slurry was prepared by reacting 12,616 gramsof aluminum pellets, 18 liters of water, and 65 grams of mercuric oxide.The reaction was started by introducing steam for four minutes into thereaction mass while stirring the same. The reaction was allowed toproceed for 1 /2 hours and then the liquid mass was filtered throughcheesecloth. The filtered alumina slurry, weighing 11,746 grams, had analumina content of 16.32 weight percent, a pH of 9.00 at 28 C. andcontained 1920 grams of alumina. One-half of the alumina slurry wasspray dried in the Niro spray dryer at an inlet temperature of 410 C.,an outlet temperature of C., and'a rate of 80 cc. per minute. The spraydried powder contained 66.5 weight percent alumina. A portion of thespray dried alumina, weighing 902 grams and containing'600 grams ofalumina, was dry mixed with 60.7 grams of molybdenum trioxide, 99% pure.The mixed powders were then calcined for 3 hours at 1200" F. and theproduct weighed 633 grams. The finished catalyst contained 9.21% M00,and the remainder being substantially all A1 7 The following series ofexamples involve the use of silica in the catalyst preparation in orderto improve the stability at elevated temperatures.

CATALYST IX The alumina was prepared by reacting 12,820 of aluminumpellets, 18 liters of distilled water and f 65 grams of mercuric oxide.The reaction was initiated by introducing live steam into the reactionmixture for a period of minutes. I ceed with continuous agitation for aperiod of 1% hours.

At the end of the reaction period, thereaction mixture was filteredthrough a cheesecloth. The filtered alumina slurry contained 15,595grams containing 7.77% solids by ignition loss, a density of 1.066 C.and a pH of 8.90 at29.5 C. p

The alumina slurry weighing 7729 grams was stirred for a 5 minute periodbefore the addition of 60.5 cc. of

silicon tetrachloride (32 grams of SiO;,). The silicontetrachloride wasadded below the surface of the slurry while stirring vigorously. After aminute period, the

pH was 1.35 at 33 C.

In an effort to raise the pH of the slurry, 100 cc. of ammoniumhydroxide (2830% ammonia) were added to the alumina. After agitating thealumina for a period' of 10 minutes, the pH was 3.67 at 31 C. Anadditional 28 cc. of concentrated ammonium hydroxide was added to thealumina. After a minute period, the alumina. has a pH of 6.08 at 28 C.Thereafter, the alumina was spray dried in a Niro unit using thefollowing conditions:

an inlet temperature of 400 C., an outlet temperature of 118 C. and afeed rate of 90 cc. per minute. The spray dried alumina Weighed 970grams. It was then calcined for a 3 hour period at 1200 F. The calcinedalumina weighed 602 grams.

The calcined alumina was impregnated with a solution containing 73.1grams of ammonium molybdate A i) s 'z z r' 2 dissolved in 500 cc. ofdistilled water. An additional 350 cc. of Water were added in order tocompletely wet the alumina. The impregnated alumina was first dried ina'The. alumina slurry was prepared by reacting 12,507

grams of aluminum pellets, 18 liters of distilled water and 65 grams ofmercuric oxide. The reaction was ini tiated by the addition of livesteam for a period of 4 minutes while continuously agitating. Thereaction was allowed to proceed for 1% hours with continuous mix ing.The reaction mixture was then filtered through a cheesecloth and thefiltered alumina slurry weighed 15,604 grams having a pH of 8.13 at 31C., a density of 1.067 grams per cc. at 50 C. and 8.38% solidsdetermined by ignition loss.

'7802 grams of alumina slurry were agitated while adding 132.0 grams ofethyl orthosilicate diluted with 100 cc. of absolute methyl alcohol. Themixture con- The reaction was allowed to programs per cc. at 40 tained apH of 8.28 at 33 C. Thereafter, the alumina,

' mainder being approximately all A1 0 CATALYST XI Catalyst X above wascalcined at'1470 F. for a period of6hour's." p

In the following example, the effect of lowering 'the pH of the aluminasol is illustrated.

CATALYST XII 7802 grams of the alumina slurry prepared in accordancewith the method described under Catalyst X were mixedwith'30 cc.of'glacial acetic acid diluted with an equal volume of water. Afterstirring for a 10 minuteperiod, the alumina contained av pH of 4.99 at31.5 C. Thereafter, the alumina was mixed with a solution containing132.0 grams of ethyl orthosilicate diluted with cc. of absolute methylalcohol. The pH of the mixture was 5.01 at 315 C.

After stirring the mixture for a 15 minute period, a solution containing83.4 grams of ammonium molybdate ((NH Mo O -4H O) dissolved in 600 cc.of distilled water was added. The catalyst solution then had a pH 'of5.95 at 29.5 C. The catalyst solution was agitated for a 1 hour periodbefore being spray dried in a Niro unit employing the followingconditions: an inlet temperature of 420 C., an outlet temperature of 113C. and a feed rate of 100 cc. per minute. The spray dried catalystpowder was then calcined for 3 hours at 1200 F. The finished catalystcontained 8.90% M00 4.93% SiO: and the remainder being approximately allA1 0 CATALYST XIII Catalyst XII was calcined for a 6 hour period at 1470F. I

For the following example,'a hydrogel of silica alumina crackingcatalyst was employed for the purpose of supplying silica to the desiredcatalyst.

CATALYST XIV The alumina slurry was prepared by reacting 12,515 gramsof; aluminum pellets, 18 liters of water, and 65 grams of mercuricoxide. The reaction was initiated by the addition of live steam for aperiod of 5 minutes while agitating continuously. The reaction proceededfor 1% hourswith continuous mixing. The reaction mixture was thenfiltered through a cheesecloth'and the filtered alumina slurry, weighing15,311 grams, had a pH of 8.88 at 29: C., a density of 1.090 grams percc. at 42- C. and 10.03% solids determined by ignition loss.

A silica-alumina cracking catalyst hydrogel was prepared in thefollowing conventional manner. A dilute solution of sodium silicate wasreacted with 26% sulfuric acid. The silica gel had a pH of 2.60, at 26.5C. The addition of aqueous ammonia raised the pH to 6.52 at 285 C. Asolution of aluminum sulfate was then added which lowered the pH to 3.09at 28 C. and re-' quired the .addition of aqueous ammonia to again raisethe pH to 6.56 at 28 C. The silica-alumina hydrogel was filtered andwashed repeatedly with acidulated water 7 until the hydrogel was free ofsodium and sulfate.

The Washed hydrogel analyzed 7.19% silica and 1.27% alumina, theremainder being water.

7655 grams of alumina slurrycontaining 767 grams ofalumina wasvigorously stirred While adding 552 grams of the above preparedsilica-alumina hydrogel slurried in 250 cc. of water. Stirring wascontinued for 20 minutes and the pH was 8.52 at 27 C. Activation wasperformed by the addition of a solution of 99.2 grams of ammoniummolybdate ((NH Mo O -4H O) dissolved in 600 cc. of water. After 15'minutes of stirring the pH was 7.50

at 27.5 C. Thereafter, the catalyst mixture was spray.

as ss eeper; minute. The spraydxiedncatalyst was then calcinedtor, 3hours at 1200 The finished catalyst contained 8.90% M 5.04% SiO, and theremainder that thepH of the alumina" so'l' was lowered.

, CATALYSTXVI v 7655. of the aluminafslurry .preparedin accordanoe-Twiththe method described under Catalyst XIV were mixed withq47'cc. ofglacial acetic acid diluted to 94 cc. with distilled water in. order to.obtain a pH of 5.00 at 2615" C. while stirring continuously for 50minutes. The

alumina slurry wasvigorbusly stirred while adding 552 grams of thesilica-aluminalhydrogel prepared as described in Catalyst XV and.slurried in 250 cc. of water. After stirring .15 minutes a solution of99.2 grams of ammonium molybdate ((NH ),Mo O -4H O) dissolved in.1'600'cc .ofwater was added to the alumina slurry. Afterxl5 minutes ofagitation, the activated slurry had a pH of 5.34. at 26 C. Thereafter,the catalyst mixture was spray dried in the Niro unit at an inlettemperature of 410 C., an outlet temperature of 117 C., and a.

feedratezof 116 cc.'per minute. The spray dried catalyst was'thencalcined for 3 hours at 1200 F. The finished catalyst contained 8.99%M00 4.95% SiO :and the remainderflbeing approximately all A120CATALYSTII Catalyst XVI was calcined lib-1470. F. for a period of 6hours.

In the :following example, the. catalyst was prepared I by dedreasing'the pH and aging the alumina sol.

CATALYST XVIII The alumina slurrywas prepared by reacting 12,500 gramsof aluminum pellets, 18 liters of distilled water and 65 :grams ofmercuric oxide. The reaction was initiated by adding live steam to themixture for a period of 7 minutes with continuous agitation thereof; The

as calcined for a hour period at.

1? Inthe following example, a smaller amount of silica was incorporatedintovthe preparation.

CATALYST 'XX The alumina slurry was pre pared by reacting 12,600 gramsof aluminum pellets, 18 liters of water, and 65 grams of mercuric oxide.The reaction was initiated by the addition of live steam for a period of4 minutes while agitating continuously. The reaction was allowedtoproceed for 1. /1 hours with continuous mixing. The liquid mass wasfiltered through a cheesecloth and the filtered alumina slurry, weighing13,859 grams, had a pH of 9.10 at 26 C.,. a density of 1.125 grams percc. at 55.S C., and 14.43% solids determined by ignition loss.

One half of the alumina slurry containing 927 grams of alumina wasvigorously stirred while adding 266 grams of silica-alumina hydrogelprepared as described in Catalyst XIV and slurried in 250 cc. of water.The pH.

of the alumina-silica slurry after stirring 15. minutes was 8.80 at27.5" C. The alumina-silica mass was then activated with a solution. .of119.5 grams of ammonium molybdate ((NlhhMo o qH O) dissolved in 600 cc.of water. After 15 minutes of stirring, the acivated slurry had a pH of6.85 at 29" C. Thereafter, the catalyst mixture was spraydried'in theNiro unit at an inlet temperature of 410 C., an outlet temperature of117 C., and

a feed rate of 1 10 cc. per minute. The spray dried catalyst wasthencalcined for 3,houi's.at 1200 F. The finished catalyst.contained.8.82% M00 1.92% SiO and the remainder being, approximatelyall A1 0 7 The relative effectiveness of the various catalysts above wasdetermined by using the same in aYlaboratory hydroforming test 'unit. Inthese. tests, a Mid-Continent naphthahavingan initialboiling point of230 F. and an reaction was allowed to proceed with stirring for a periodof 1% hours. The reaction mixture was Lfiltered through a cheeseclothand the filtered slurry weighed 17,335 grams; The slurry had a pH of8;82;at 26 C., a density of.1;044 grams .per cc. at 49 C. and contained6.58% solids by ignition loss.

86617.5: grams of. aluminazsluri'ytweresmixedrwith :30'cc.

of .glacial acetic acid diluted with an equal volume of.

water. ThepI-I of the alumina was 4.55 at 32 C. The alumina was allowedto age for a period ofI17 /2 hours. After aging the alumina, a solutioncontaining 115 grams I of ethyl orthosilicate diluted with 5100 .cc.. oftechnical perature; of 114 C.,.and a feed rate of 71 .cc. 'per minute,

The spray.driedcatalyst.powderwas'then calcined for a 3.ho ur period at1200 The finished catalyst contained 8.84% M00 4.95% SiO andtheremainder Sbeing approidmately all alumina.

. CATALYSTJXIX oarslystxvui was calcined W147i)" F. for a periodattenuate I I Y endpoint of 430 F. was used. This naphtha had anoctanemumber (CFRM). of 30 and contained approximately 9% aromatics byvolume. The reactor of the testunit had 550cc; capacity. The catalystsin suitable quantities were charged to the reactor; Hydrogen waspressure'of the system was released and then purged with nitrogen; Thecatalyst was then heated to'about 950 F. and air was introducedalongwiththe nitrogen. The concentration of air was regulated to produce amaximum temperature of 1050 F. in the'catalyst bed. During thisoperation the temperature at various points in the bed was ascertainedwith two thermocouples, one located in the upper. part and the other inthe lower part of the bed.

The flow of nitrogen and air through the reactor was con tinued forabout A- hour, afterthe temperature dropped to. about 950 F. Followinganother nitrogen purge, the

system was again placed under hydrogen pressure for about l-hour,whilethe hydrogen rate and temperature to a zo' anen barrel containing400 grams of new aluminum pellets, 12,216 grams of used aluminum pelletsI and ISIiters-Of distilled water. A 7" blade stirrer on a l al H.PL'IightningmiXer, used for agitation, was placed close to the bottom ofthe barrel. Additional stirring was accomplished by manually moving thealuminum pellets with a 3*fo0t stick. To start the reaction, live steamwas run into the mixture until boiling occurred, which took 4 minutes;After 1.58hours, the produced alumina slurry was filtered through acheesecloth.

The weight of the slurry was 11,746 grams. was'9.00 at"28 C. An ignitionloss reported 16.32%

'solids'fwhicHindicated 1920 'grams of A1 0 were formed.

It s pH purpose of improving the stability" as alumina. Catalyst IX Wasprepared by the; addition of silicon tetrachloride .to the alumina in;order to etf ect emm- ' monium molybdate to. the' sl u rry ot alumina, 7results .obtainedlwith this catalyst show..that.a more selectivereaction is? effectedthan Catalyst'll' whichinvolved the additionoffammonium molybdat'eto calcined a; greater; stability of the catalystat angeleyateditelmpera ture. .Whencompa'ring Catalyst IXjwithCatalys't}IL it'lis noted that; the, selectivity, jrieasuredth ,yieldiof (2 free liquid at: 85 ,j CFRR octane number, is greater Heretofore;the talys was d'o'uel mfi the A the .ca 'al' t; at elevatedtemperatures. 1 It is unexpected observe that than the ,selectivity of1; Catalyst addition? Cof silica to molybdenay .the selectivity of thejcatalyst shouldfimpr'oveiby the addition of silica, because-normallysilica ctmsidrred to be a cracking componentfland, therefore;'thegreater yield of: liquidKproduct is not anticipatedtin a hydro=forming process. In: the'case', .off Catais't X, silica was added in thefornr ofethyl silicate. Comparing Catalyst X with Catalyst 11and'jcatalyst IX, it is'to be observ'edthat. the addition" of silica inthe form of an organic silicate results inla catalyst of greaterselectivity and. activity than. a 1 catalyst. v vithou t silica}: and;one which contains silica through the addition. of. silicon.

tetrachloride. Clearly therefore, the incorporation, of

silica by means of an organic. silicate, such as for example, the alkylsilicates, the'aryl silicates; the allgaryl silicates, the aralkylsilicates, etc.;-produ'ces. a; catalyst .of improved selectivity andactivitywhen thelalumina,

of the. catalyst has been prepared in. the manner armspresentinvention'. V H gl4 a Z I Catalyst XI wasobtained by thecalcination of atalyst X at a temperature of 1470f F. aiid;iforffihotil:s; It; is

hown in Table! that the selectivity of-{this catalyst decreased.slightly as ar'esult of "calcinationi -whereas .the. activity increasedsignificantly. In Catalyst-XII the pH of the alumina sol' was lowered bytheaddition r,

.acetic acid. This was done to study the efiect of lowering the; pH ofthe alumina upon (catalyst, selectivity' and i he "111W iQ m. the aboveremarks it appears that a s lica con:

Fro taining 'catalystlwhich was. prepared-by the. use of silicaaluminmcracking catalyst hydrogel, should, be subjectedto.anadditionahhigh;temperature;treatment in order to improvethe-activity and selectivity. Accordingly, such a cata1lyst should besubjected; toa temperature of at least about 1200" F. and thistemperature can be as high as about 1:600. E preferably the temperaturetreatmntr Should. be effected at. a temperature of about 145 0 toabout1600"; The period of treatment may vary namabout'i hour to about'lzhours, however rn ore usually, about 4 hours-togaboutlit hoursl Thesilica-alurnina crajcltihgi cetaljyst 'hydrogel-can; be any, gel typegsilicaa alumina material. containing about 70' to about 99%silicabased. on. thetotal weight of the gel. The remainder of the; gelconstitutsf alumina s sensati n was c i cndins app i N 4 2. 923... lMQYZL Having thus'provideda description. of my invention with. specificexamples, it should be underStoQd that no undueilimitat'ioiisorientations are to; be imposed by reason thereof," but that the. scopeof; the present inventionis, defined by the; appended claims.

1. A method 'of preparing acatalyst consisting essentially of reactingaluminum; water and a compound of a metal selectedfrom 'the groupconsisting of mercury, zinc and cadmium in an amount from 0.0005 toabout 0.1 pound per pound of aluminum at a temperature of at least about150 F. to prodilce alumina in a slurryhaving a pH between about 7 .5 andabout 9.5; combining the alumina with a; suitable: precursor material ofa catalytic-agent{selected from the U group consisting of molybdenumoxide and platinum and subjecting the mixproduce a catalytic a'gentsupported on the alumina.

aetivityi It is torbe noted from' Catalyst XII thattheQ selectivity;increased slightlyg whereas' {the actiyityj isw substantially the same.-t l-t appears; therefore,"'that the lowering of the pH of the aluminasol may not have adverse effects upon catalystproperty. Catalyst XIV isa silica containing catalyst which was prepared byxthe use ofsilica-alumina cracking catalyst hydrogel. As a Quite'unexpectedly it isobserved thatflthe selectivity- .and activity of the calcined catalystincreases T phenomenon is unusual because it might be expected that theactivity would increase somewhabby high. temperature. treatment and notthe selectivity thereof. The preparation of .Catalyst XIV was varied by.lowering the pH of the alumina sol and this is shown as Catalyst XVI.From Table I it is to be noted that as a result of lowering the pH inthe catalyst preparationythe l'seleq tivity andactivity improvedslightly. CataIyst XVI was subjected to a calcination treatment at l470F; for a 6 hourperiod and the resultant catalyst is CatalystXVIL It isto be observed by a comparisonof CatalystIXVI that the. selectivity ofthe catalyst improved significantly;

whereas the activity decreased. This is contrary to expectations,because lone might suppose both. the activity and selectivity mightincrease ;slightly, but not as much as the results show. Catalyst is; asilica containing catalyst which was ,preparedby :the use of 2. Amjethod'of, producing a catalyst consisting essentially ofreacting-aluminum, water and. a compound of a e al se e dfrom the roe-con i t f m r y. zinc and cadmium in an amount frornD OOOS. to about0.1 pound per-'1 pound of aluminum ata temperature of at least about 150F. to produce alumina in a slurry havinga pH. between about 7.5 andabjout9. 5;. combining a silica forining substance; the alumina andfasuitable pre- "group consisting of molybdenum ox de and platinum;

zinc and cadmium in an amount from 0.0005 to about 0.1

silica-alumina cracking catalyst;v hydrogeh The silica concentrate wasapproximately lone-half ofpwhat was mpl i nth P epar rt-Ca a ys l Ii 9.

cursor material of a catalytic agent'selected from the and subjectingthe resultant; mixture to an elevated temperature .sutficientto producea .catalyst containing the. catalytic. agent supported on. alumina andsilica.

3,. The method of claim ;2 wherein the silica forming substance is anorganic silicate,and the alumina is prepared aft a temperature of aboutto about 300 F.

4. The method ofclaiml wherein the silica forming substan e is asilica-alumina gel containing aboutVO to about 99% by weight of silica.

5. The methodof claim 3 wherein is an alkyl ester of silicic acid.

"6. The method of; claim 4 which further characterized by subjectingithefinishedcatalyst to atreatment the-organic silicate at a temperature ofabout 1200" to about lfiQOf F. for a period suflicientto improve theselectivity and activity of the catalyst. v

7. A method of preparing a catalyst consisting essentially ofreactingaluminum, water and an oxide of a metal selected from the groupconsisting of mercury,

pound per pound of aluminum at a temperature of about 175 to about 300F. to produce a slurry of alumina h vi ap twe a o d ham -5. w i s heslur y f a u a w t a pr rsor ma ria o m y a li h y denum oxide in aquantity suflicient to produce a finished catalyst containing about 0.1to about 30% of molybdenum oxide, and subjecting the resultant mixtureto a calcination treatment for a period sufiicient to produce thefinished catalyst.

8. A method of preparing a catalyst consisting essentially of reactingaluminum, water and mercuric oxide in an amount from 0.0005 to about 0.1pound per pound of aluminum at a temperature of about 175 to about 300 Fcombining the resultant alumina with an alkaline agent to raise the pHto at least about 8.5 and aging the alkalized alumina for a period of atleast about hours, combining the aged alumina with ammonium molybdate ina quantity sufficient to produce the finished catalyst containing about0.1 to about 30% of molybdenum oxide, and subjecting the resultantmixture to a calcination treatment to convert the ammonium molybdate tomolybdenum oxide.

9. The method of preparing a catalyst consisting essentially of reactingaluminum, water and mercuric oxide in an amount from 0.0005 to about 0.1pound per pound of aluminum at a temperature of about 175 to about 300F. to produce a slurry of alumina having a pH between about 7.5 andabout 9.5, combining the slurry of alumina with ethyl orthosilicate in aquantity sufiicient to produce the finished catalyst containing about0.5 to about of silica and ammonium molybdate in a quantity sufiicientto produce the finished catalyst containing about 0.1 to about 30% ofmolybdenum oxide, and calcining the resultant mixture for a periodsuflicient to convert the ammonium molybdate to molybdenum oxide and theethyl orthosilicate to silica.

10. The method of producing a catalyst consisting essentially ofreacting aluminum, water and mercuric oxide in an amount from 0.0005 toabout 0.1 pound per pound of aluminum at a temperature of about 175 toabout 300 F. to produce alumina in a slurry having a pH between about7.5 and about 9.5, combining the alumina with a silica-alumina gelcontaining about to about 99% of silica. in a quantity suificient toproduce a finished catalyst containing 0.5 to about 15% of silica andammonium molybdate in a quantity sufficient to produce a finishedcatalyst containing about 0.1 to about 30% of molybdenum oxide,subjecting the resultant mixture to a calcination treatment for a periodsuflicient to convert the ammonium molybdate to molybdenum oxide, andfurther treating the finished catalyst at a temperature of about 1450 toabout 1600 F. in order to enhance the activity and selectivity thereof.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,196 Heard Oct. 6, 1942 1,868,499 Guertler July 26, 1932 2,217,865Groll et al. Oct. 15, 1940 2,274,633 Pitzer Mar. 3, 1942 2,288,336 Weltyet al. June 30, 1942 2,371,237 Heard .1 Mar. 13, 1945 2,422,372 Smith eta1. June 17, 1947 2,432,286 Claussen et al. Dec. 9, 1947 2,448,960Connolly Sept. 7, 1948 2,449,847 Heard Sept. 21, 1948 2,461,959 BrandonFeb. 15, 1949 2,469,314 'Ryland etal. May 3, 1949 2,487,466 Nahin Nov.8, 1949 2,582,428 Haensel Ian. 15, 1952 OTHER REFERENCES Publication:Thermal Transformations of Aluminas, Stumpf et al., July 1950, Ind. andEng. Chem, vol. 42, pages 1398-1403.

UNITED STATES PATENT QFFICE CERTIFICATE OF CORREGHN Patent No 2,840,5291958 Philip A, Lofranoois It is hereby certified that error appears inthe printed specification of tlde' above numbered patent requiringcorrection and that the said Letters Patent should read as correctedbelow.

column 16 lino Column 8 line 24, before "alumina" insert the g for."faoial" read 59,, for "285 on read. 2805 ci oolunm 13, line a,glaci'ab Signed. and sealed this 14th day of October 19580 (SEAL)Attest:

KARL H, AXLINE ROBERT C. WATSON Commissioner of Patents AttestingOfficer

2.A METHOD OF PRODUCING A CATALYST CONSISTING ESSENTIALLY OF REACTINGALUMINUM, WATER AND A COMPOUND OF A METAL SELECTED FROM THE GROUPCONSISTING OF MERCURY, ZINC AND CADMIUM IN AN AMOUNT FROM 0.0005 TOABOUT 0.1 POUND PER POUND OF ALUMINUM AT A TEMPERATURE OF AT LEAST ABOUT150*F. TO PRODUCE ALUMINA IN A SLURRY HAVING A PH BETWEEN ABOUT 7.5 ANDABOUT 9.5; COMBINING A SILICA FORMING SUBSTNCE, THE ALUMINA AND ASUITABLE PRECURSOR MATERIAL OF A CATALYTIC AGENT SELECTED FROM THE GROUPCONSISTING OF MOLYBDNUM OXIDE AND PLATINUM; AND SUBJECTING THE RESULTANTMIXTURE TO AN ELEVATED TEMPERATURE SUFFICIENT TO PRODUCE A CATALYSTCONTAINING THE CATALYTIC SUPPORTED ON ALUMINA AND SILICA.